Solid-phase micro-extraction (SPME) uses a polymer-coated fiber to extract and concentrate VOCs and SVOCs from the headspace above a sample, or from an aqueous-phase sample. The fiber is then removed and desorbed in the inlet of the GC or GC–MS. It is most commonly used for analysis of flavours, fragrances and odours in the food, beverage and consumer products industries.
Markes International’s fully automated Centri system allows unattended SPME sampling, with or without secondary re-focusing. Trap-based cryogen-free focusing results in enhanced sensitivity by allowing multiple extraction cycles from a single sample to be ‘concentrated’ in one GC–MS run, and results in improved peak shape and higher signal-to-noise ratios for the most volatile, early-eluting species.